Apparatus fob regulating current or potential in secondary of transformers



2 Sheets-Sheet 1.

(No Model.) THOMSON.

APPARATUS FOR REGULATING CURRENT OR POTENTIAL IN SECONDARY OF TRANSFORMERS.

No. 400,515. Patented Apr. 2, 1889.

(No Model.) 2 Sheets-Sheet 2.

E. THOMSON.

APPARATUS FOR REGULATING CURRENT 0R POTENTIAL IN SECONDARY OF TRANSFORMERS.

Patented Apr. 2, 1889.

5 m, vewi oz Eli Z a Z71 02715071 AT OFFICE- ,ELIHU Thomson, OF LYNN, MASSACHUSETTS-a Y APrAR/lws FOR nreuumuc CURRENT or POTENTIAL m stccuom or rmsronuzns,

sincmoanon forming part qf utte 'ratmt No. 400,515, dated April 9, Iss9.

' PPHMQOI nos-ma ic, 1m. flsriall'o. 206,018. mom.)

To all whom it may concern: I

zen of the United States, and a resident of Lynn, in the county off/Essex and State of Massachusetts, have invented a certain new audus'eful Apparatus for Regulating Current or Potential in Secondary of Transformers, of

. which the following isa specification.

My invention relates to that class of elec tric apparatus in which two coils or currents are brought into inductive relation, one of said coils being-the seat oISaIternating cur-- rents induced by alternations or other variations of current inthe other.-

The object of my invention is to so construct a device of this kind that it shall have a self-regulating character, resulting in air antomatic adjustment or regulation of the current or potential in the coil forming the secondary when the resistance or current in the same varies. I This self-regulating character is especially useful in cases where the inducing-coil is supplied from a source of constant potential, and by proper construction of the apparatus a regulation may be secured which will give a. constant current in the induced circuit despite changes of resistance, although the inducing-current is connected continually to the'constant-pote'ntial source. Thus if the primary coil of a converter be attached to a constant-potential circuit as a branch the current which I am enabled to obtain in the secondary circuit may, instead of being approximately of. constant potential like the primary,

be of approximately constant strengthor volume of flow regardless of a wide range of (lit fcrences of resistance interposed in such secondary circuit; or, again, I may obtain from the secondary an electro-motive force or potential which diminishes as the current strength increases, as when. resistance is gradually taken out-of the secondary circuit. My invention is particularly applicable to v the running of arc lamps by induction from constant-potential mains without the use of resistances in circuit with the arcs for limiting the current which they receive, since by the use of my invention anyincrease in the secondary may be made to produces fall of electramotive force given out by the secondary coil feeding thearc. Were this not the case, or were the electromotive force maintained, the current flowing to the arc lamps Be it known that-l, Enmn 'lHoMsoN; a ci't-i-- would be unstable, and the lamps would be very irregular in action, owing to the fact that as the current in the arc increases the resistance of the arc falls, which would with constant potential bring about further. current increase, and so on. In my invention it the current is to be ten amperes for the arcs it cannot rise much above that amount, no

matter whether the carbons in the are are ing without resistance of one, or more of the lamps while the current in the circuit of the remainder is substantially unchanged. In fact, by proper modifications in the manner of carrying out my invention, the primary coil being on constant potential, the second ary coil may be short-cirouited and retain only the normal or a slightlydncreased current; I am not aware that this has ever been done before.

My invention consists, essentially, in the which is included in the alternating or vary-- ing current circuit, and has parts, as herein-' after described, brought into definite proximity to form a partial magnetic closure of the magnetic circuit of said core of a definite or .s'et'value, according to the nature of the regulation of current or potential desired in the induced-circuit, such magnetic circuit being formed independently of the magnetic circuit which threads both'coils of the converter.'

The invention consists, further, in a converter having primary and secondary coils disposedon difierent parts of the same core, parts or extensions of which are broughtinto definite proximity, seas to form-a magnetic shunt of definite or set value for the part ofthe core includedv by each coil. The shunting thus provided will be automatically varied as-the current in the secondary coil varies and will be, increased in amount as the current in- IOO proved details of construction and combinations of forms 'of core.

re show adjustable devices and modifications oftions of parts, to be hereinafter more particularly described, and then specified in the claims.

In the accompanying drawings,- Figures 1 and 2 are elevation and plan views of a coil containin or operating inacoordance with my invention. Figs. 3, 4, and'5" are modifica Figs. 6, 7, 8, and 9 the inventiom Figs. 10, 11, 12,-and"]i3 show modifications of forms and arrangement of the parts. Figs. 14, 15,and 16 illustrate some of the uses of my inventionI 'Fig. 17 is a diagram showing current andpotential. Fig. 18 shows modified'devices giving similar ef fects to the foregoing. ig. 19 is adjustable core in one of my coils. p

In Figs. 1 and. 2, a b are alternating-current mains at constant poteutialdifierence, or apin strength and. to be selE-regulated'through proximately that.

P is a primary c011 of'insulated wire of 'turnscorresponding to the-potential between in P when the circuit of S isopen.

S is a secondary coil of suitable number of turns according to potential .of current to be obtained-therefrom; A laminatedor other a and 12, such that verylittle current passes core, I, passes through both fcoils, P and 'S,as

shown, and makes a closed magnetic circuit. At 2 e' are'projections from the laminae of 1 I the core; .By these projections the core is ex tended to include an air-space between the parts of the core' at' K., The width of this space K may be in some cases quite narrow, and in other cases 6 and e maybe well separated, as shown. The purpose is to provide an air or magnetic resistance-shunt to the parts of the core '1, coming from the coilsand joining their cores. The space K mightbe filled in whole 'or part with solid or liquid substances not highly magnetic, such as wood, paper, slate, &c. The coil so organized has the peculiar property of producing in the secondary coil S a droop or fall of electro-motive force when the resistance is cut out of its circuit, and this fall may be made nearly proportional to the"fall of resistance, or di-' minishing resistance'which may be inserted in its circuit. 1

At A is represented an arc lamp, (or A'm'ay stand for a series ofarc lamps,)' which may thus be fedwith constant current, although primary coil P is subject to constant potentials. I

By means of theprojections e e'or other magnetic, carriers or A conductors the magnetism developed in the portion of core surrounded by the coil P can work, as it were, through two magnetic circuits, one including the space or resistance K and the other including the portion of core passingv through the coil S The magnetic lines developed by the core or coil P, which pass through the airspace at K and escape the coil S, produce wholly self-inductive eflects, resulting in an opposition to the flow of the primary currents,

a. form of while all thelin es developed by the coil i which pass through the axis of the coil S, result, as usual, in the production of secondary currents. Any tendency to increase of current fiowin'g-iucoii P, resulting from the lowering of the resistance in the circuit of S, will atonce be followed by increased self-induction of the coil'P through the increased close ure of the magnetic circuit of its core across the space K, while at the same time the self-induction'of the coil S will also increase, owin to the increased closure of the magnetic circuit of its core across the same space. In fact, the, elfect of a slight increase of current in the coil S would beto heat back thelines of force tending 'topass through its coils from the coil P and cause-them to be shunted across the space K.

The result of all this is that the. varying resistance in the circuit of the secondary S receives a current'which tends to be limited":

the provision of the shunting magnetic space K. The partial magnetic shuntat K may be also provided at other points than that shown in Figs. 1 and 2. In Fig. 3 itis-at e e','K

being beyond the secondary coil S. In this case also the coils Pand S might be interchanged in position on the core I I.

current induced in S. The nearer e and e' approach, the smaller the current given out in S, and vice versa. The distance affects but little the potential of coil S on open circuit; but when S'isput to work -its possible ice current becomes limited inaccordance l'with the space 'betw'eene and e.' I sometimes vary the action by inserting in the lines of force formed in the space of partial magnetic 'elosme, as in'Fig. 7, a 'conductor such as a cop per-plate, Kto a greater less extent between the faces 2 e; The eflect is to cut off in part the passage of magnetism through the air between e and e bythe induction in the conductor of currents which oppose the magnetic effects. If, as in Fig. 8, the copper-plate '-K' behung on a movable support, such as lever L, and be inserted part way between the faces ,ec', as shown, the plate will'whenthe current is on tend to be repelled from the slot. The spring Z may be adjusted to partly balance the piece K. still furtherperfects the action in delivering .a constant current, alternating, of course,

from the coil S.' s 1 In Fig; 9, K is a frame 'of copper, and Z is The addition-of this device s a counter-balance. This is used as in Fig.8,

K being inserted in the space K, Fig. 1, andset so that when current is on coil P it is' balanced in a position part way.iu the space K, as in Fig.8, .the secondary 8 being at the same time in circuit with its normal highestthe resistance interposed exceeds its proper limits, Where the current to be obtained is to have properties between those due to constant-potential average and constant-currentaverage, the modification, Fig. 10, may be adopted. One coil, S, or part of the secondary winding is near the coil P, or adjacent thereto, (or under or overlying the same,) and the other part of the secondary is, as at .S, removed therefrom on the same core. In this case the terminals of the secondary coils in in the secondary be diminished the current will increase but at a less rate than constant potential would give, so that 'a limited current of moderate strength flows even on short circuit.

Fig. 11 shows the invention applied to ring induction-coils. Between each primary coil P and secondary S the iron of the core is extended to approach and form a magnetic shunt of high resistance around each coil. In Fig. 12 the core itself is formed of an interior ring wound with coils P and S, the, and an outer closely-enveloping ring, which may be joined between each alternate coil with the ringcore. The magnetic shunting occurs at e e ee'eeee'.

Fig. 13 shows a ring-core with only two coils, P and S, and magnetic shunt of comparat-ively high resistance at e e'. To construct the apparatus the core may be cut in halves or otherwise suitably divided, as on the line X- X, and the coils wound separately and put in place over the meeting ends of the cores. In Fig. 19 this form is shown with means for adjusting the distance between the parts e e. In this case e is made as a plug or sliding piece, which may be moved up or down to govern the space between the faces of e and e or the. resistance 'of the shunt.

Fig. 14 shows my improved induction-coil magnetic,

- involving the feature of magnetic shunting,

as before described, running a series of incandescent lights or other working resistances from the coil S, while coil P is on a constantpotential alternating circuit from a b. When the adjustments are properly made, one or even all the lights L L may be shunted by switches of no resistance, and the current in the circuit of S will be substantially unchanged in amount-i. e., the potential of the coil S isselt-adjusting to the resistance in the circuit unless the latter be too great.-

Fig.'15 shows how a wire, L, may be main tained at a uniform temperature while its length in circuit may be greatly varied owingto constant current strength obtained note withstanding constant potentials at a b.

For arc-light work or for electric furnaces or heating, as in Fig. 16, my invention permits distribution-at constant potential to the coils and feeding to the work, as at A, currents of constant volume, or, as before indicated, of a volume much. less increasing than in the ratio of constant potential over the resistance in circuit. 4 a

Fig. 18 illustrates a modification in the manner of applying the device, Fig.1, to prime and secondary circuits. The induction-co l P S is of ordinary or any suitable character, and the automatic regulation is produced by the coils P 'S' in circuit with P S, respect ively, and applied to a core with the partial niagnetic shunt. The shunt operatesin the manner already described to lower the potential of the secondary. In this case, however, as in Fig. 10, the droop 0! potential will not be in ratio to give a constant current; but the increase of current will be measurably limited by the action of the shunt for the core of coils P S-. 3

I do not herein claim the method of determining the current or potential in the secondary consisting in developing alternating magnetism thrgugh the action of the current in the primary or secondary, or both, and variably closing the magnetic circuit through a path independent in whole or in part of the core in which magnetism is devoloped by the other coil, asthis method forms the subject of another application for patent filed of even date herewith.

In Fig. 17 the verticals or ordinates may represent potentials developed in a secondary, S, with varying resistances, and the horizontals or abscissas the strength of the currents flowing. The continuous curve line starting at two hundred becomes nearly vertical at one hundred, showing that from this point down at any less potential than one hundred the-current will remain practically the same. shows the condition of partial regulation in which there is a continued fall of potential accompanying an increase of current. These curves may be called characteristics of the apparatus, and will vary, as before stated, according to the construction and proportions.

What I claim as my invention is 1. An induction-coil or transformer having a partial magnetic shunt of determinate capacity for the magnetism threading the coils, whereby the potential of the secondary cur rent may be automatically lowered on an increase of such current, as and for the purpose described. v

2. In an induction-coil or transformer, spar The dotted or broken curved line I tially=closedmagnetic circuit consisting of polar extensions or magnetic carriers from the- 'parts of the core between the primary and secondary: brought into close-proximity, as

and for the purpose described.

'3l The combination, withan induction-coilor transformer having a magnetic shunt,'of a conductor suspended or movable in the shun ting-lincs of force, as and for the purpose de- 2 ing the currents in the-secondary, so as to keep or tend to keep the same of constant amount, as and for the purpose described.

5. The izombinatiomwith an iron corethreading two alternating-current coils, of magnetic carriers or extensions for said core brought into close proximity and forming a magnetic shunt variablein amount automatically by the increase or decrease of current in one of.

said coils, as described.

"'1 6;;The combination, with. two alternating- Iciir'rentcoils placed in inductive relation upon coil.

a suitable core, of a magnetic shunt for the magnetism threading said coils and of definite or determinate strength increasing automatically with an increase of current in-the 7. The combination, with two alternatingcurrent coils wound on ditferent parts of the same'core, of iron masses tending to form a magnetic shunt for the portions of core between the coils and adjustable for the purpose of determinzitin g the amount of the magnetic shunting.

8. The combination, with constaut-poten tial mains, of a transformer having its primary fed therefrom, a secondary on a differ- .ent portion of core, and a partial magnetic shunt for the portion of core between thecoils. 9. The combination, with the primary, of two secondaries connected in series and applied to diiferent parts of the same core, one

near to and the other more remote from the pri- Y mary, and a partial magnetic shunt for the core, as and for the purpose described.

10. The combination, with two alternatingcu'rrent mains, of transformers having a variable resistance in their secondaries and partial magnetic shunts for the portion of cores threading the secondaries, as and for the purpose described.

11'. A system of distribution for are lighting, comprising constant-potential mains, trans formers in .multipleon said mains, arc-light circuits connected to the secondaries, and potential-regulators consisting of partiallyclo'sedmagnetic circuits set up by the currents of either or both of said'coils.

12. The combination,with primary and secondary alternating circuits in inductive relation, of an iron core forming a seat of altermating magnetism developed by one of said circuits, and having extensions brought into close proximity to form a partially-closed magnetic circuit of determinate amount variable automatically with the currents flowing.

ondary alternating-current circuits in inductive relation, of an iron core forming. the seat,

-of alternating magnetism developed by the I current in the secondary and extensions from 'said core brought into proximity to form a partially-closed magnetic circuit of definite or-determinate amount. I

14. The combination, with an alternatingcu'rrent main, of a transformer having a variable resistance in its secondary and a core which forms the seat of magnetism developed by the secondary currents, and is provided with extensions brought into proximity to form a partially-closed magnetic circuit of determinate amount, as and for the purpose described.

' '15. The combination, withan induction-coil or converter, of a-partially-closed magnetic circuit excited by the current in each or either v.of-the electric circuits and a conducting-plate movably suspended in a gap in such magnetic circuit, as and for the purpose described.

16. The combination,with an induction-coil or converter, of magnetic carriers-such as iron-core extensionsfrom a core excited by the current which flows in one of the coils of the converter, and means for adjusting the magnetic resistance between the parts of the core. partially shunted by said carriers or extensions, as and for the purpose described.

17. An induction-coil or converter having an endless iron core or magnetic circuit on which the primary and secondary coils are disposed at difierent points, and having parts or extensions of said core brought into determinate magnetic inductive proximity to form a partially-closed magnetic circuit of definite capacity independent of the closed magnetic cir lzuit over the iron core and through the cm s. v

18. An induction-coil or converter having P y d secondary conductors wound on.

diifercnt parts of the core, and having parts of said core brought into proximity but separated by a magnetic shunting-space of definite or determinate capacity, as described, properfor keeping the current in the secondary approximately constant when the primary is supplied from a constant-potential source.

Signed at Lynn, in the county of Essex and State of Massachusetts, this 31st day of December, A. I). 1888.

ELIHU THOMSON; Witnesses:

J. W. GIBBONEY,

E. W Rron, Jr.

' 13. The combinatiomwith primary and sec- 

